Description

Levodopa is the metabolic precursor of dopamine. It crosses the blood-brain barrier and is converted to dopamine in the brain. Carbidopa increases the amount of levodopa that is transported into the CNS by inhibiting the decarboxylation of peripheral levodopa. Entacapone is a selective inhibitor of COMT which alters the pharmacokinetics of levodopa, resulting to increased and more sustained levodopa serum levels.

Symptomatic postural hypotension may occur when levodopa is added to the treatment of patients already receiving antihypertensive. Dose adjustment of the antihypertensive agent may be required. Dopamine receptor antagonists (e.g. some antipsychotics and antiemetics), phenytoin and papaverine may reduce the therapeutic effect of levodopa. Patients taking these medicinal products with levodopa/ carbidopa/ entacapone combination should be carefully observed for loss of therapeutic response. Since levodopa competes with certain amino acids, the absorption of Levodopa, Carbidopa & Entacapone may be impaired in some patients on high protein diet.

Narrow-angle glaucoma, phaeochromocytoma, history of neuroleptic malignant syndrome (NMS) and/ or non-traumatic rhabdomyolysis. Severe hepatic impairment. Concurrent use of or within 14 days of discontinuing non-selective MAOIs.

Common side effects include dyskinesia, nausea, hyperkinesia, change in urine color, diarrhea and stomach pain. Other side effects may include diarrhea, sometimes severe; colitis; hallucinations; other mental disturbances; orthostatic hypotension; rhabdomyolysis; and symptoms resembling neuroleptic malignant syndrome (a condition characterized by high fever, muscle stiffness, and confusion); fibrosis; skin cancer, etc.

Pregnancy category C. The combination of levodopa/ carbidopa/ entacapone should not be used during pregnancy unless the potential benefit justifies the potential risk to the fetus. The safety of this combination in the infant is not known. Women should not breast-feed during treatment with this combination.

Levodopa, carbidopa and entacapone together may cause dizziness and symptomatic orthostatism. Therefore, caution should be exercised when driving or using machines. As with levodopa, periodic evaluations of hepatic, hematopoietic, cardiovascular and renal function are recommended during extended therapy.